The Pro version of 3G Watchdog distinguishes between measured and billable usages. The measured usage is the raw traffic between the phone and the Internet as observed from the phone. The billable usage is obtained by applying billing rules such as count in block, do not count uploads, do not count usage from some applications, etc… to the measured usage. These billing rules vary largely depending on operators and plans. You can configure them in the “Billing rules” section of 3GW’s settings.
The billable usage is more likely to be close to your operator’s numbers, that’s why all alerts in 3GW are based on billable usage. Likewise the usage shown in the usage graphs (report screen) is the billable usage.
Limitation: billing rules only apply to local (domestic) plan mobile usage, not to roaming or Wifi usages.